1. Field of the Invention
The present invention relates to computers, and more specifically, to autonomic reclamation processing for tapes.
2. Description of Related Art
Prior art teaches file systems which are stored on tapes such as the linear tape file system (LTFS). A file system on tape is denoted by an index, which represents metadata of the file system structure. This metadata includes a mapping of files to block addresses on tape. This metadata is typically stored on a file system formatted tape as well.
The Linear Tape File System (LTFS) is a tape file system that works in conjunction with Linear Tape Open Generation 5 (LTO-5) tape. LTFS allows mounting a LTO-5 tape cartridge, which is loaded in a LTO-5 tape drive as a file system in a server and store data on the LTO-5 tape cartridge just like in a common file system. LTFS uses the LTO-5 capabilities to create partitions on one LTO-5 tape. One partition is used to store the file system index and the other partition is used to store the file system data. The data format in which the file system index and the file system data are written is described in the LTFS format specification. The format of the file system index written to partition 1 is based on XML. From a tape perspective LTFS is like a storage management application reading and writing date from and to tape.
A tape cannot be written in a random fashion but rather sequentially from the beginning to the end. Thus it is not possible to write data to any position on tape but only at the position where the last write operation ended. When data on a tape needs to be overwritten then the tape must be written from the beginning. Over time data, which has been written to tape, expires which causes data to become inactive. The remaining data is active.